1. Field of the Disclosure
Embodiments disclosed herein generally relate to methods and apparatus to grip tubular members. More specifically, embodiments disclosed herein relate to an apparatus that is used to guide and grip one or more tubular members, such as oilfield tubular members as the tubular members are disposed downhole.
2. Background Art
In oilfield exploration and production operations, various oilfield tubular members are used to perform important tasks, including, but not limited to, drilling the wellbore and casing a drilled wellbore. For example, a long assembly of drill pipes, known in the industry as a drill string, may be used to rotate a drill bit at a distal end to create the wellbore. Furthermore, after a wellbore has been created, a casing string may be disposed downhole into the wellbore and cemented in place to stabilize, reinforce, or isolate (among other functions) portions of the wellbore. As such, strings of drill pipe and casing may be connected together, such as end-to-end by threaded connections, in which a female “pin” member of a first tubular member is configured to threadably engage a corresponding male “box” member of a second tubular member. Alternatively, a casing string may be made-up of a series of male-male ended casing joints coupled together by female-female couplers. The process by which the threaded connections are assembled is called “making-up” a threaded connection, and the process by which the connections are disassembled is referred to “breaking-out” the threaded connection. As would be understood by one having ordinary skill, individual pieces (or “joints”) of oilfield tubular members may come in a variety of weights, diameters, configurations, and lengths.
Referring to FIG. 1, a perspective view is shown of one embodiment of a drilling rig 101 used to run one or more tubular members 111 (e.g., casing, drill pipe, etc.) downhole into a wellbore 113. As shown, the drilling rig 101 includes a frame structure known as a “derrick” 102, from which a traveling block 103 (which may include a top drive) suspends a lifting apparatus 105 (e.g., an elevator or a tubular (e.g., casing) running tool connected to the quill of a top drive) and a gripping apparatus 107 (e.g., slip assembly or “spider”) at the rig floor may be used to manipulate (e.g., raise, lower, rotate, hold, etc.) a tubular member 111. The traveling block 103 is a device that is suspended from at or near the top of the derrick 102, in which the traveling block 103 may move up-and-down (i.e., vertically as depicted) to raise and/or lower the tubular member 111. The traveling block 103 may be a simple “pulley-style” block and may have a hook from which objects below (e.g., lifting apparatus 105 and/or top drive) may be suspended. Drilling rig 101 can be a land or offshore rig (e.g., drill ship) without departing from the spirit of the invention.
Additionally, the lifting apparatus 105 may be coupled below the traveling block 103 (and/or a top drive if present) to selectively grab or release a tubular member 111 as the tubular member 111 is to be raised and/or lowered within and from the derrick 102. As such, the top drive may include one or more guiding rails and/or a track disposed adjacent to the top drive, in which the guiding rails or track may be used to support and guide the top drive as the top drive is raised and/or lowered within the derrick. An example of a top drive is disclosed within U.S. Pat. No. 4,449,596, filed on Aug. 3, 1982, and entitled “Drilling of Wells with Top Drive Unit,” which is incorporated herein by reference.
Typically, a lifting apparatus 105 includes movable gripping members (e.g., slip assemblies) attached thereto and movable between a retracted (e.g., disengaged) position and an engaged position. In the engaged position, the lifting apparatus 105 supports the tubular member 111 such the tubular member 111 may be lifted and/or lowered, and rotated if so equipped, e.g., by using a lifting apparatus that is a tubular (e.g., casing) running tool connected to the quill of the top drive. In the retracted position, the lifting apparatus 105 may release the tubular member 111 and move away therefrom to allow the tubular member 111 to be engaged with or removed from the lifting apparatus 105 and/or the gripping apparatus 107. For example, the lifting apparatus 105 may release the tubular member 111 after the tubular member 111 is threadably connected to a tubular string 115 supported by the gripping apparatus 107 (e.g., slip assembly or “spider”) at the rig floor at the floor of the drilling rig 101.
Further, in an embodiment in which the drilling rig 101 includes a top drive and a tubular running tool, the tubular member 111 may be supported and gripped by the tubular running tool connected to the quill of the top drive. For example, the tubular running tool may include one or more gripping members that may move radially inward and/or radially outward. In such embodiments, these gripping members of a tubular running tool may move radially outward to grip an internal surface of the tubular member 111, such as with an internal gripping device and/or the gripping members of the tubular running tool may move radially inward to grip an external surface of the tubular member 111, such as with an external gripping device, however so equipped.
As such, the gripping apparatus 107 of the drilling rig 101 may be used to support and suspend the tubular string 115, e.g., by gripping, from the drilling rig 101, e.g., supported by the rig floor 109 or by a rotary table thereof. The gripping apparatus 107 may be disposed within the rig floor 109, such as flush with the rig floor 109, or may extend above the rig floor 109, as shown. As such, the gripping apparatus 107 may be used to suspend the tubular string 115, e.g., while one or more tubular members 111 are connected or disconnected from the tubular string 115.
Referring now to FIGS. 2A and 2B, a gripping device 201 that may be included as the lifting apparatus 105 and/or the gripping apparatus 107 of the drilling rig 101 is shown. For example, in addition or in alternative to a gripping device, a lifting apparatus 105 and/or the gripping apparatus 107 may comprise a supporting device may be used that supports one or more tubular members within a drilling rig, such as supporting a tubular string of tubular members suspended from a drilling rig. An example of a supporting device is disclosed within U.S. Pat. No. 6,651,737, filed on Jan. 24, 2001, and entitled “Collar Load Support system and Method,” which is incorporated herein by reference.
The illustrated gripping device 201 includes a bowl 203 with a plurality of slip assemblies 205 movably disposed therein. Specifically, the slip assemblies 205 may be connected to a ring 207, in which the ring 207 may be connected to the bowl 203 through an actuator (e.g., actuator rods) 209. Actuator may be actuated, such as electrically actuated and/or fluidly (e.g., hydraulically) actuated, to move up and/or down with respect to the bowl 203, in which the slip assemblies 205 connected to the ring 207 may correspondingly move up and/or down with respect to the bowl 203.
The illustrated slip assemblies 205 are designed to engage and contact the inner tapered surface of the bowl 203 when moving with respect to the bowl 203. Bowl 203 is shown as a continuous surface but may comprise non-continuous surfaces (e.g., a surface adjacent to the rear of each slip assembly 205). Thus, as the slip assemblies 205 move up or down with respect to the bowl 203, the slip assemblies 205 may travel down along an inner surface of the bowl 203. With this movement, an inner surface (e.g., die) of the slip assemblies 205 will grip a tubular member 211 disposed within the gripping device 201. The slip assemblies 205 may have a gripping surface (e.g., teeth) on the inner surface to facilitate the gripping of the tubular member 211. After the tubular member 211 is supported by the gripping device 201, additional tubular members may be connected or disconnected from the tubular member 211.
As shown with respect to FIGS. 2A and 2B, the gripping device 201 may be used to grip tubular members 211 having multiple outer diameters. For example, as shown in FIG. 2A, the slip assemblies 205 may be positioned within the bowl 203 of the gripping device 201 to grip a tubular member 211A having a first diameter D1. As discussed, the slip assemblies 205 may be positioned using the ring 207 that may be vertically moveable, e.g., through the actuator rods 209. FIG. 2B shows gripping device 201, in which the slip assemblies 205 are positioned vertically higher within the bowl 203 with respect to the positioning of the slip assemblies 205 shown in FIG. 2A. As such, this positioning of the slip assemblies 205 in FIG. 2B enables the gripping device 201 to grip another tubular member 211B, in which the tubular member 211B has a second outer diameter D2 larger than the first outer diameter D1 of the tubular member 211A (for example, where D1 and D2 are on a tubular body itself and not a connector portion thereof). Thus, gripping device 201 may grip tubular members 211 having a large range of outer diameters without the need of reconfiguration and/or adding supplemental equipment to the gripping device 201. For example, in one embodiment, the second outer diameter D2 may be at least 145 percent larger (or smaller) than the first outer diameter D1.
A tubular string of tubular members may be heavy, in the magnitude of several hundreds of thousands of pounds. As such, the gripping devices handling these tubular strings, in addition to the drilling rig and other components thereof, must be equipped to handle such weight. Further, tubular members of the tubular string, such as casing, may have a relatively thin wall, in which the tubular members may be crushed or partially deformed if excessive force is applied by the gripping device. Additionally, the weight of the tubular string may be even further magnified, such as when drilling offshore, as the tubular string may need to extend through the water to reach the borehole, which may be in the magnitude of several thousands of feet, if not more. For example, the tubular string may have one or more different tubular members or tubular sections, such as including a section within the tubular string having casing, drill pipe, and/or a landing string, in which each of these sections of the tubular string may have different dimensions (internal diameter and/or external diameter) adding to the overall weight of the tubular string. Adding length to the tubular string only further increases the weight that the gripping devices, drilling rig, and other components thereof must be equipped to handle, an equipping process that may significantly increase the cost of for drilling.
To offset at least some of the weight of the tubular string (which may include a casing string or other tubular string hung from a distal end thereof), floatation modules have been developed that may be connected to or otherwise disposed about (e.g., about the OD of) a tubular member 311. One or more floatation modules 315 may be connected to the tubular member 311, such as by having a hinge formed on one side of the floatation module 315 that enables the floatation module 315 to, for example, clasp around the tubular member 311 from a lateral side thereof. Additionally or alternatively, a floatation module may be attached or applied to the tubular member, such as by applying as a coating or attached via other means, e.g., adhesive, to retain the floatation module stationary with respect to the tubular member. Depicted floatation modules 315 have a generally circular profile (e.g., a cylinder). However, floatation modules 315 may have any shape, such as a rectangular or hexagonal profile or spherical shape, that enables the floatation modules to connect to the tubular member 311.
A floatation module is commonly formed from a buoyant material or buoyant structure, such as having foam (e.g., high density foam) or plastic and/or having a housing with a fluid (e.g., gas) disposed therein for buoyancy. As such, this buoyant material or buoyant structure for the floatation module 315 may be used to offset at least some of the weight of the tubular member 311, e.g., from the drilling rig 101, and thus a tubular string altogether, as the floatation module 315 may be connected to the tubular member 311. A floatation module 315 may be used within the water, e.g., seawater of an offshore drilling operation, and/or a floatation module 315 may be disposed within a wellbore, including the riser, in land or offshore drilling operations. As such, a floatation module 315 may provide a buoyancy force when disposed within water and/or mud of a drilling operation, in which the buoyancy force of the floatation modules 315 may be used to offset at least some of the weight of the tubular string, e.g., from the drilling rig 101.
Further, a floatation module, may be used with a landing string, such as when a landing string is used to dispose (e.g., “land”) one or more tubular members, such as casing, within a wellbore in a deep water offshore operation. The landing string, which may exceed tens of thousands of feet in axial length to reach between the sea floor and the drilling rig (e.g., a floating drilling platform or ship), may include one or more floatation modules 315 connected thereto or otherwise disposed about to offset some of the weight of the landing string and the other tubular string (e.g., casing). As such, the floatation modules may relieve, at least a portion, of the stress applied to the landing string, other tubular string, and drilling rig equipment used for the operation.
However, as a floatation module may be formed from a generally buoyant material and/or as a generally buoyant structure (e.g., forming the floatation module with, at least a portion of, foam) a floatation module may lack strength and/or rigidity, e.g., the floatation module may be easily damaged. For example, a floatation module may be particularly susceptible to damage when assembling and/or disassembling a tubular string of tubular members together and/or disposing (e.g., raising or lowering) the tubular string within and/or through a gripping or supporting device (as discussed herein).
One example may be that, as a floatation module is disposed through a bore of a gripping or supporting device of a drilling rig, one or more of the components of the gripping or supporting device, such as the slip assemblies of the gripping device having a gripping surface (e.g., teeth) or other damage inducing surface or component of a gripping or supporting device, may contact and thus damage (e.g., dislodge) the floatation module. For further example, a gripping surface of a slip assembly (e.g., teeth) contacting a foam portion of a floatation module may damage (e.g., abrade or puncture) the flotation module. As such, damage to a floatation module may be magnified if a tubular member which the floatation module is connected to is not properly aligned within a bore of a gripping or supporting device during movement therethrough. Accordingly, there exists a need to prevent damage to a floatation module connected to a tubular member, as any damage to the floatation module may increase the loads applied to the drilling rig.